Easy opening carton



July 3, W5 6 w. WAGNER, JR 2,753,1U4

EASY OPENING CARTON Filed Sept. 1, 1954 INVENTbR v I .4- E 24% BY 7% 7; 6 2 4 g w.) ATTORNEYS M W A M 4 7 7 V 2 k 5 fi V w d M 4 4/ j 0/ a w 27. w 3 V u I IIAI fl Ill W1 4y 7 a a lllnitcd States Patent Ofiice EASY OPENING CARTON Wilmer W. Wagner, Jr., Baltimore, Md., assignor, by mesne assignments, to The Patent and Licensing Corporation, New York, N. Y., a corporation of Massachusetts This invention relates to cartons or shipping containers constructed of cardboard, fiberboard, pasteboard, corrugated board or the like and is directed more particularly to cartons of the type having a bottom, side walls, and a top formed of flaps hingedly connected to the side walls and adhesively or otherwise connected together in overlapping relationship.

It is well known that cartons of the class described are often exceedingly ditlicult to open by hand. As the carton must withstand rough handling, stacking, dropping without rupture or appreciable deformation even with contents of heavy weight, the material employed must be of high bursting and tear strength and the adhesive or other securing means of extreme tenacity. The manual opening of such a box requires almost brute strength and it is frequently necessary to employ knives or other cutting means to gain access to the interior thereof.

As a solution to this problem, it has been suggested to localize the areas to which the adhesive is applied or to provide one or more of the flaps with perforations defining removable sections, adhesive being interposed between these sections and overlapping areas of other flaps. In either case, it is difficult to arrive at a balanced condition where the carton may be readily opened by hand but will not accidentally come apart during handling, shipping, etc. In the latter case, the result of easy accessibility is often not attained due to incomplete or mis-spaced perforations and opening is in many instances defective, the non-removable fiap sections being torn or split by the separating action deviating from the lines of perforation.

it is therefore the object of this invention to provide an easy opening carton in which certain of the adhesively connected flaps are formed with removable sections incompletely defined so as to be readily detachable but to resist accidental separation.

A further object of the invention is to provide a carton having overlapping sealing flaps secured together substantially throughout their overlapping area, wherein to facilitate opening sections of the overlapping portions of certain of the flaps are detachable from the remainder of the flaps and are retained by the flaps to which they are secured, the attachment of the remaining portions of the certain flaps preventing accidental opening of the carton but being separable upon intentional opening thereof.

Another object of the invention is to provide a carton having overlapping sealing flaps, certain of which have sections detachable from each other and the remainder thereof, the detachable sections being so defined as to avoid undesirable tearing of the remainder of the flaps during opening of the box by deviation of the separating action from the lines of definition.

Other objects and advantages of the invention will be revealed by the following detailed description when considered in connection with the accompanying drawings in which,

Fig. 1 is a perspective view of an assembled carton designed in accordance with this invention, the normally 2,753,104 Patented July 3, 1956 overlying flaps being shown open to reveal the novel inner flap construction;

Fig. 2 is a sectional view taken along line 2--2 of Fig. 1;

Fig. 3 is an enlarged plan view of one of the inner flaps;

Fig. 4 is a fragmentary section of an inner flap taken along line 4-4 of Fig. 3; and

Fig. 5 is a plan view of the blank from. which the novel carton is formed.

In general, the carton of the present invention includes a bottom, side walls, and a top wall formed by flaps joined to the upper edges of the side walls, which flaps are folded over and secured in overlapping relationship during the sealing or closing operation. Certain of the flaps, the inner flaps, for example, are provided with adjacent sections at the inner end thereof which are detachable during opening from the remainder of these flaps, the detachable sections being separated from each other by a shear line and being connected to the remaining section by a line of perforation extending over the major portion of the common periphery. In the preferred embodiment, the line of perforation extends at right angles to the shear line separating removable sections and to eliminate tearing beyond the line of perforation in the direction of the shear line of that flap section which remains attached to the carton, the shear line is given a smooth right-angular bend on both sides prior to its connection with. the line of perforation.

Turning now to a detailed description of the invention, it will be seen from Figures 1 and 5 that the carton is of one-piece construction and comprises the principal side wall panels 11, i2, 13 and i4 hingedly connected together by means of the usual score lines. Projecting from one of the end panels and hingedly connected thereto is a tab 15 which is adapted to be secured to the free edge of the other end panel by means of staples, adhesive, or the like to form a rectangular tube-like body. To close off the lower opening of this body, a bottom 21 is provided which may take any one of many well known constructions, for example, a plurality of bottom flaps 22, 23, 24 and 25, each hingedly connected to the lower edge of one of the side Wall panels, which flaps are folded inwardly into overlapping relationship and secured in this position by means of adhesives, staples, or the like. The top of the carton is also formed in the usual manner from flaps 31, 32, 33 and 34 hingedly connected to the upper edges of side wall panels 11-14 which flaps are adapted to be folded inwardly and secured in overlapping relationship to seal the carton. As is common, opposite pairs of the top flaps, when in sealed or closed relationship, occupy a common plane and at least one of these opposite pairs, preferably the outer pair 32, 34, when in juxtaposed position, have a combined area equal to that enclosed by the four side walls so that the upper surface of the top is formed wholly by the pair of flaps. It is also usual for the inner edges of this pair to meet at the center line of the box although this is not altogether necessary and the line of juncture between this pair may be offset with respect to the center line if desired, it being understood that, in any event, this pair is coterminus, which is to say, that they meet at a substantially common line. Generally, the combined area of the other pair of flaps, inner flaps 31, 33, is less than that encompassed by the carton so that the inner edges of these flaps are spaced apart.

Now in accordance with the novel aspects of this invention, one of these opposite pairs of flaps, preferably inner pair 31, 33, is provided with removable sections which during opening of the carton are detached from the remainder thereof and move with and as a part of the overlying flaps 32, 34. For this purpose, a shear line or slit 35 is formed in each of inner flaps 31, 33, beginning at the inner edge thereof and extending transsections 31a, 3111,3312, 33b and a section 310, 33c 'rei'mains-"attachedto the side walls of the carton. It is contemplated by this'i'nvention that where, as is the nor- "malcase, adhesives or 'glue is used as the means for se- Theextent offthe'inner p I attached to 'the 'carton 'willvary in accordance withj the versely .ofthatedgeamaior portionpf, the distan e. o. he axis of the hinge connection of the flap to its corresponding side wall. Preferably, the shear 35 is interrupted fonvery short distances, say about a quarter inch, at one or more points along its length to provide a tab-like con- 1nection36 between the detachable portions of the flap which connection tends to resist. or prevent unintentional separation of these portions. At its. inner termination, the shear line 35 joins or connects with a line of perforation. 37; extending on either side thereof parallel to the inner edge of the flap and toward its side edges. The perforation line 37 stretches from the shear line 35 over a major portion of the distance to the side edge of the help but a minor portion of that distance, as at 38, is left fully connected to the remainder of the flap for a purpose to bedi'scu'ssed shortly.

I have observed that if the shear 35 makes a sharp right angular intersection with the perforation line 37,

there is a tendency when the box is opened and the removable-portions pulled apart for the separating action not to follow the line of perforation but to proceed into the portion of the. flap which remains attached to the side wall with the result that the perforation lines are ineffectr al. I To prevent-such anoccurrence, the inner termination of the shear line is branched and smoothly curved in a right angle bend prior to its juncture with the line of perforation on both sides thereof as at 39. Thus, when the box is opened the separating action follows the shear 'line 35 around the curved portion thereof and is already moving in the direction of the perforation line before the same is encountered; consequently, the tendency is for the action to continue to move in that direction and to proceedalong line of perforation rather than to depart therefrom.

. Itwill thus be seen that, in broad terms, the shear line 35, the perforation line 37 and the side edges define on each of the inner fiaps 31, 33 two adjacent removable which curing the overlapping flap portions in sealed relationship 'thatadhesive would be applied substantially throughout J the entireoverlapping'area, which is to say, that where the: adhesive'is applied onthe inner flaps it would be applied substantially over' the full area thereof, on the attached sections 310, 330 as well as on the detachable sectiohs 31a, 31b, and 33a, 33b, as indicated by the stippling Fig. 1. I Alternatively, if the adhesive is to be applied to the 'overlying'fiaps 32, 34, then; at least the end-portions thereof corresponding to thearea of the inner flaps :ove'rlapped thereby would bevirt ually completely covered.

Where other means of attachment is d'esirable,.that means would be: used on the attached sections of the flap as well aslthedetachablesections thereof. The reasoning behindthispractice is that if the attachment meanswere used only on the detachable sections of the flap and, due to rough handling, these sections should become separatedfror'n the remainder of the flap, the outer flaps would the swing'outwardly, leaving the box open. However, j by. using the'attachment means throughout the overlapped area the connection between the attached inner flap sec- ;tion and the overlyingouter flap not only serves to maintain 'the box closed even though the detachable sections should become separated, but also tends to resist such separation.

flap area which should be left eyeball: dimensions of the carton and,"'perhap's, with the 4 of about, 8 inches, and. an inner flap length of about 5% inches, the length of the flap section which remains attached to the carton is about 2% inches, and except for very small or very large boxes, a variation of plus or minus one-half inch from this figure would be permissible, the longer flap section for larger boxes and the shorter flap section for smaller boxes. 7

The unperforated connection between the attached and detachable inner flap sections has generally the same function as that of the attached flap section, i. e., to assist in maintaining the 'top flaps in operative or closed relationship notwithstanding rupture of the perforation line 37. As wasv also the case with the attached flap section, the extent of this un per fora'ted connection will vary between boxes of different dimensions'although it too should in all cases be less than one-half of the distance from the shear line 35 to the side edge of the flap. In a box having the dimensions previously specified, I have found an unperforated section of about 1 /4 inches to be particularly satisfactory and except for very large and very small boxes, a variation of about plus or minus one-fourth inch will be'permissible and desirable. In similar fashion, the radius of curvature of the bend in the branched end of the shear line may vary among various types of boxes. In the box already identified, a radius of three-fourths inch is advantageous and for most boxes a'change of plus or minus one-fourth inch will accomplish the desired result.

The procedure. for opening the carton will be more or less apparent. The medial portions of the outer flaps 32, 34 are grasped in turn and-pulled open, rupturing the tabs, 36 and. he perforations of corresponding sections 31a, 33a or 31b, 33b, as the case may be, and tearing the unperforated connection 38. Because of the momentum developed during the initial phases of the opening action, the connections 38 do not present substantial resistancebut give way relatively easily so that the use of undue force is not necessary.

, An important feature of cartons constructed in the manner just described is that special or elaborate equipiment is not required; the blank can be formed on a standard printer-slotter machine and the other steps, such as glue application and sealing, can be carried out with conventionalapparatus. Such machinery is available in any carton-making factory and, consequently, the manufacture of cartons-embodying the principles of this invention could be r eadilyinstitu ted with only such minor adjustments in such machinery as is ordinarily necessary and a major capital expenditure is wholly unnecessary.

The carton rnay, of course, be provided with any of the secondary features usually found on similar cartons, such as punch-ins 40 useful for carrying purposes. It S will be unders tood by those skilled'in the art that certain of the functional elements in the invention may be rearranged or varied in configuration, dimensions, etc., all without departing from the spirit of the invention except as may be defined in the appended claim.

Having thus described my invention, that which is claimed is:

An easy openingpaperboard rectangular container for articles comprising two oppositely disposed end walls, two oppositely disp'osed'side walls, abottom and a top, said 'top comprising end flaps ofsub'stantially equal size extending from the'said en'd'walls, respectively, and folded toward onei'an'other, a perforated tear lineextending between the lateral edges of said end flaps closer to the top edge of said' respective e n'd wa'lls than to the outer edges of said end flaps, a single interrupted Sllt'lIl each of'said end. flaps extending. substantially perpendicularly from the outer edges of said end'iflaps to. a point adjacent to 'jthe said] perforated tear'lin'e thereinQsaidi s'lit 'bein'gjbi- 5 fur'ca't'ed at the said'point to form two branches smoothly curvedin opposite directions to connect said slit'v vith jsaid'te'ar Jine, side flaps 'of. s'ubst antially equal size extending, respectively,'from the upper edges'of'said side Walls, said side flaps being folded toward one another to overlie said end flaps with their outer edges substantially abutting, and said side flaps being adapted to be adhesively secured to said underlying end flaps.

References Cited in the file of this patent UNITED STATES PATENTS 2,002,364 Daller May 21, 1935 6 Mott Mar. 28, 1939 Donnelly Oct. 21, 1941 Nelson Feb. 29, 1944 MacArthur d. Aug. 3, 1954 Nute et al July 19, 1955 

